⚠ The Float Reverses If Growth StopsLow threat

Costco Wholesale (COST) — threat to the moat

The cash that arrives because the business is expanding is not a moat, and it leaves the way it came.

Costco's balance sheet works because two liabilities keep growing: deferred membership fees, and money owed to suppliers. At the third quarter of fiscal 2026 accounts payable of $22,363 million exceeded merchandise inventories of $19,418 million by $2,945 million, and deferred membership fees stood at $3,157 million1. Total current liabilities of $42,125 million exceeded total current assets of $45,177 million by less than eight percent, on a company holding nearly $20 billion of cash.

Change in accounts payable inside operating cash flow ($M)-$382MFY2023 outflow+$1,938MFY2024 inflow+$404MFY2025 inflowBars show magnitude; FY2023 was an outflow of $382M. The release reverses when growth stops.
Costco's $13,335M of operating cash flow against $8,099M of net income contains a component that exists only because the business is expanding. That component is not a moat.

This is a virtuous arrangement in one direction only. Growth means each period's collections exceed the prior period's, so the float rises and funds itself. Stagnation means it stops rising, and the cash flow that came from the increase disappears — not a loss, but the removal of a source that has been present for decades and is not visible as such in the income statement.

Decline is worse and is what happened to weaker retailers in every credit event of the past forty years. Falling sales shrink inventories, which shrink payables faster than they shrink cash; falling sign-ups shrink deferred revenue; and the working-capital release that flatters a growing retailer reverses into a drain. Costco's protection is that it holds $19,996 million of cash and short-term investments against $5,670 million of long-term debt2, which is several years of cushion.

The point is not that the float is fragile. It is that the reported operating cash flow of $13,335 million in fiscal 2025 against net income of $8,099 million3 contains a component that exists because the business is expanding, and that component is not a moat. Watch the change in payables and deferred fees inside the cash flow statement; if it turns negative for more than a year while sales are flat, the cash generation on this page is smaller than it appears.

References
  1. Moat Explorer calcAt the third quarter of fiscal 2026 accounts payable of $22,363 million exceeded merchandise inventories of $19,418 million by $2,945 million, and deferred membership fees stood at $3,157 million.
    Moat Explorer calculation - arithmetic on figures reported in Costco's Form 10-K and Form 10-Q: accounts payable less merchandise inventories ($1,667M at FY2025 and $2,945M at Q3 FY2026), foods and sundries plus fresh foods ($147,552M), Executive memberships over paid memberships (38.7M / 81.0M = 47.8%), accrued member rewards over gross margin dollars ($2,677M / $30,026M = 8.9%), the $1,250 reward cap divided by the 2% rate ($62,500), and Other International revenue as a share of the total — FY2025 and Q3 FY2026 · publ. September 2026 · source ↗
  2. ReportedCostco's protection is that it holds $19,996 million of cash and short-term investments against $5,670 million of long-term debt, which is several years of cushion.
    Costco Form 10-Q, quarter ended May 10, 2026 - condensed financial statements and notes (total revenue $70,527M, operating income $2,815M, diluted EPS $4.93, balance sheet, segment table, 928 warehouses) — Q3 FY2026 and the first 36 weeks · publ. June 3, 2026 · source ↗
  3. ReportedIt is that the reported operating cash flow of $13,335 million in fiscal 2025 against net income of $8,099 million contains a component that exists because the business is expanding, and that component is not a moat.
    Costco Form 10-K, fiscal year ended August 31, 2025 - consolidated financial statements and notes (income statement, balance sheet, Note 11 segment reporting, disaggregated revenue by merchandise category, legal proceedings) — FY2025 · publ. October 8, 2025 · source ↗
Sources
Generated September 23, 2026